Method of tempering soles



May 9, 1944. w. E. PHINNEY METHOD 0? TEMPERING SOLES File d may 12, 1942 Patente d May 9, 1944 William E. Phinney,

Cambridge, Mass, assignor,

by mesne assignments, to United Shoe Machine ery Corporation, Boston, Mass, a corporation of 7 New Jersey Application. May 12, 1942, Serial No. 442,623

It has also been found that excessive softening '14 Claims.

Thi invention relates to methods of tempering unattached leather soles to prepare them for laying and subsequent bottoming operations in shoemaking. It is herein set forth with regard to-the requirements of outsoles for welt shoes, but i it may also be used to temper soles for other types of shoes.

Modern procedure in factories that produce welt shoes allots nearly two hours for the series of bottoming operations that begins with sole-fv laying and ends with heel-attaching which is usually the last operation before bottom-finishing operations. Good shoemaking requires the outsoles to be in a state of temper not only for laying but also forleveling and all the intermediate operations. scouring and subsequent bottom-finishing operations require the grain sides of the soles to be dry, for if they are not dry when they reach the bottom-scouring stage progress. must be halted On the other hand,bottom-- until they are dry. For this reason many shoe I factories in which closely calculated schedules of production must be maintained are obliged to use drying cabinets to prepare the soles for bottomfinishing, but this drying procedure retards production, require additional handling and apparatus, and disrupts the normal and orderly progress of the work.

It is common practice now to immerse unattached soles in water in one prolonged stage from fifteen minutes to one hour or more, and mull them in a cabin et from twelve to forty-eight hours, but that treatment overloads themwith water, renders their grain surfaces sodden and necessitates artificial drying when the shoes reach the bottom finishing stage.

With regard to the objectionable result above mentioned, and others making industry, the object of the present invention is to provide improvements in methods of tempering soles whereby delays in output may,

be avoided and better results obtained not onlyin well known to the shoesome of the bottoming operationsbut also in the finished product.

It has been found by experience, in evolving the present invention, that tempering with watervapor alone will produce a nice state of temper if continued long enough, and that soles so tem pered do not finally dried, pered. Nevertheless, such treatment must. be continued about twelve hours or more, according to the thickness and density of the leather, to permeate the entire thickness of thesoles aslebecome appreciably stiffer, when than they were before being temquired for rough-rounding, channeling, stitching,

and leveling.

of the surfaces of leather with water before the interior strata become by restricting the periods of wetting to about two tempered can be avoided minutes each, or less, provided each wetting is followed immediately by a stage of treatment with warm water-vapor of long enough duration to= diffuse the charges of water through the pores of the leather.

lihe evenness of temper thus produced without rendering the surfaces sodden is presumably due to the manner of breaking down the resistance of the tanning substances in the leather. Some of these are'soluble in water and if not softened.

they act-as barriers against permeation of the leather by vapor. On the other hand, they should.-

not be washed away as they would be by too long 1 periods of wetting. The oily substances used fors loading sole leather are not soluble in water but may be softened by heat. retained in the leather, but they, too, act as barriers against permeation. Nevertheless, their resistance to permeation may be reduced by heat of a degree that will soften them without removing them. The problem, as now understood, is 1 to introduce water, vapor or both into the interior strata of the leather in the shortest time without robbing the leather of its tanning substances and without rendering its surfaces sodden. A period of wetting restricted to two minute will soften some of the tanning substances without washing them away and without rendering the surfaces of the leather sodden, but iinot followed immediately by a period of treatment with warm vapor some of the water left on the surfaces will evaporate. Rapid tempering requires some force to carry water into by the tanner. Hence, heat is'the force that softens the oily substances enough to enable capillary action to carry the water into the inner strata, and that the vapor not only prevents evaporation of the surface water but actually supplements it with additional moiso.

ture. Then, when capillary action ha dispersed the water of one wetting, another short wetting will load the surfaces of theleather with more water, and so on, each stage of warm vapor serving to promote capillary action, and each influx of water serving to promote the tempering process and at the same time to carry the watersoluble substances into the leather with it.

These should also be the leather despite the barrier. provided by the substances put into the leather -r it is supposed that the Whether or not the foregoing analysis is corroot, the fact is that satisfactory tempering can be accomplished by this procedure in about" forty-eight minutes with thick soles of closegrained leather,

illustrated and described plication, Serial No. 458,277, filed 1942, by Walter P. Abell.

and in about twenty-eight minutes with soles of medium thickness.

A typical example of treatment provided by this invention may consist in four stages of wetting, preferably by immersion, of two minutes each with water preferably at a temperature of about 98 F., each followed by a stage of treatment of about five minutes duration with watervapor of about the same temperature. Nearly the same results could be obtained with eight stages of wetting of about one minute each and eight five-minute stages of treatment with vapor. In any case, the final stage should be one of vapor treatment of long enough duration to dispel or disperse all water from the surfaces of the soles, but it is not necessary to begin the tempering with a stage of wetting. On the contrary, a stage of vapor prior to the first stage of wetting will render the soles more receptive to water without in any way impairing the quality of the results.

The method herein set forth. may be practiced with an apparatus of the type shown in the accompanying drawing which provides a receptacle 20 having a treatment chamber deep enough to contain water 23 of the desired depth for immersion and a vapor space 22 above the water in which the soles 28 may be supported out of contact with the water. The receptacle should have a cover H and this should remain closed throughout the process of treatment to conserve the heat and the vapor. Any preferred heating means 43 may be used to maintain the desired temperature of the water and the vapor above it. Moreover, the receptacle should be provided with foraminous work-supporting means 40 arranged to carry the soles into and out of the water without opening the cover.

For the most desirable results the hee1seat portions of the soles should not be wetted. Ac-

cordingly, the soles should be placed in the worksupport to stand upright on their toe ends and when immersed the work-support should be depressed only far enough to immerse their foreparts and shanks.

To obtain the desired state of temper in the shortest time requires a large volume of vapor in the upper part of the treatment chamber and forced circulation of the vapor between and around the soles. The invention provides for both by supplying many small jets of air under pressure from perforations in an air-pipe I33 immersed in the water and relieving the pressure in the chamber through a small vent 3!; or more than one at or near the top of the vapor space. These jets of air, emitted below the surface of the water, produce a constant bubbling action and liberate large quantities of vapor. Moreover, the air is heated by the water and becomes saturated with vapor which it carries at accelerated velocity through the vapor space where soles supported in its path of flow toward the vent will absorb as much heat and vapor as they can while the surplus vapor flows through the vent to the outer atmosphere. The openings in the bottoms and sides of the work-support enable the vapor to flow freely between and around the soles standing therein and thence through the open top of the support to the vent above it.

The illustrated apparatus constitutes the subject-matter of a related development more fully in a co-pending ap- September 14, To facilitate compari- 61, wheel 63 and an electric switch 45, and a regulator son of the drawings of that application and this the same reference numerals are used to identify details common to both. In addition to the details identified above, the following are also indicated: a base I9, a work cage 21 having guiding lugs 3| and 32, vertical tracks 30, vertically adjustable stops 34, blocks 35 and connecting straps 33; flanges 31 having holes 38 for pins 39, cords 29 by which the soles are loosely tied in bundles, slats 4| for supporting the wire mesh 40, an elevator TI, 65, 64 and 68, a stuffing box 66, a crank shaft 59, a pressure-regulating valve I 3.4 in the air pipe I33, a thermostat 46,

In addition to affording the results hereinbefore described,this method of treatment avoids staining the grain surfaces of soles. Moreover, separating the soles one from another is entirely unnecessary if the periodic immersions are interspersed with periodic stages of vapor treatment of the prescribed duration. The essential consideration concerning the stages of wetting is that they should not be so long as to render sodden the surfaces of the leather, and that concerning the stages of vapor is that they should be long enough to effect uniform dispersion of the water that remains on or in the soles after each wetting.

If these considerations be satisfied, soles loosely tied in bundles may be brought to a satisfactory state of temper in forty-eight minutes or less, ac-

cording to their thickness, density and tannage; their grain surfaces will not be so soft as to be wrinkled in the process of being channeled; their condition for rough-rounding and stitching will be excellent; and in about two hours after the tempering treatment their grain surfaces will be in satisfactory condition for scouring without artificial drying.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. That improvement in methods of tempering unattached leather soles which consists in subjecting them to a series of individual stages of wetting with water each of duration too short to render their surfaces sodden, and subjecting them to alternate stages of water-vapor each of duration sufiicient to disperse the water left on v their surfaces by the wetting stages.

2. That improvement in methods of tempering consists in sub- I unattached leather soles which jecting them to a series of individual stages of wetting with warm water each of duration too short to render their surfaces sodden, and subjecting them to alternate stages of warm watervapor each of duration suificient to disperse the water left on their surfaces by the wetting stages.

3. That improvement in methods of tempering unattached leather soles which consists in sub 'jecting them to a series of individual stages of immersion in warm water each of duration too short to render their surfaces sodden, and subjecting them to alternate stages of Warm watervapor'of duration sufiicient to disperse the water left on their surfaces by the immersion stages.

4. That improvement in methods of tempering unattached leather soles which consists in enclosing them in a treatment chamber containing warm water and having a vapor space above the latter, sub ectlng the soles to a series of indi vidual stages of immersion in the warm water soles from said chamber at the conclusion of the last stage of treatment with vapor.

5. That improvement in methods of tempering unattached leather soles which consists in enclosing them in a treatment chamber containing warm water and having a vapor space above the latter, subjecting the foreparts and the shanks but not the heel seat parts of the soles to a series of individual stages of immersion in the warm water without rendering their surfaces sodden, subjecting the soles to alternate stages of treatment with warm water-vapor in said vapor space, and removing the soles from said chambers at the conclusion of the last stage of treatment with vapor.

6. That improvement in methods of tempering unattached leather soles which consists in enclosing them in a vented treatment chamber containing warm water and having a vapor space above the latter, subjecting the soles to a series of individual stages of immersion in the warm water without rendering their surfaces sodden and to alternate stages of treatment with warm water-vapor in said vapor space, removing the soles from said chamber at the conclusion of the last stage of treatment with vapor, and. forcing many small jets of air into the warm water below its surface during the stages of treatment with vapor to accelerate the transfer of vapor to the soles.

'7. That improvement in methods of tempering unattached leather soles which consists in enclosing them in a treatment chamber containing warm water and having a vapor space above the latter, moving the soles down and up in said chamber at intervals with a series of dwells in the water and a series of dwells out of the water, and circulating warm water-vapor between and around the soles after each dwell in the water.

8. That improvement in methods of tempering unattached leather soles which consists in assembling them in face-to-face contact to form one or more stacks and loosely tying each stack to facilitate handling, enclosing one or more of such stacks in a vented treatment chamber containing warm Water and having a vapor space above the water, subjecting the soles to a series of stages of immersion in the warm water and to a stage of warm water-vapor after each stage of immersion.

9. That improvement in methods of tempering unattached leather soles which consists in enclosing them in a treatment chamber containing warm water and having a vapor space above the water, subjecting the soles to a series of relatively short stages of immersion in the warm water and to longer stages of warm water-vapor in alternation therewith, the duration of the vapor stages being long enough to remove all free water from the surfaces of the soles.

10. That improvement in methods of tempering unattached leather soles which consists in subjecting them to a series of individual stages of wetting with water and to alternate stages of water-vapor.

11. That improvement in methods of tempering unattached leather soles which consists in subjecting them to a series of individual stages of immersion in warm water and to alternate stages of warm water-vapor.

12. That improvement in methods of tempering unattached leather soles which consists in subjecting them to a series of individual stages of immersion in warm water and to alternate stages of warm water-vapor enclosed with and rising from the water, and terminating the treatment with the last stage of vapor.

13. That improvement in methods of tempering unattached leather soles which consists in enclosing them in a treatment chamber containing warm water and warm water-vapor above the water, subjecting the heel seat parts of the soles to one prolonged stage of treatment with vapor without immersing them in the water, and simultaneously subjecting the shanks and the foreparts of the soles to a series of relatively short individual stages of immersion in the water and to a series of stages in the vapor.

14. That improvement in methods of tempering unattached leather soles which consists in tying a stack of soles loosely in face-to-face contact to form a bundle, immersing the foreparts and shanks of the soles in warm water, removing the soles from the water, and forcing warm water-vapor between and around the soles until all surface water on them has been absorbed.

WILLIAM E. PHINNEY. 

